Ammonia and tar recovery process



l. BECKER.

AMMONIA AND TAR RECOVERY PROCESS.

APPLICATION FILED AUG.21, 1919.

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AMMONIA AND TAR RECOVERY-PROCESS.'

APPLICATION FILED AUG.2II i919. ll. Patented Apr. 19, 1921.

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1. BECKER.' AMMONIA AND TAR RECOVERY PROCESS.

APPLICATION FILEB` AUG. 2.1, |919.

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I. BECKER.

AMMUNIA AND TAR' RECOVERY PROCESS.

APPLICATION FILED AUG.2I, 1919. 1,375.43.,

4 SHEETS-SHEET 4- Patsntd Apr. i9, 923.

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Josera Bacana, or r'rrrssjozaen, "PENNSYLVANIA, assroNor. 'ro THE Koreans colararraor rr'rfrssnneu, rnNNsYLveNia, a oonronarroiv or PENNSYLVANIA.

MMBT AND TAR RECOVERY PROCESS.

.Specification of Letters atent.

Patented Apr. 319., 192i.

.application filed .august 21, 1919. Sexrial No. 318,908.

To all whom it may cof/wem.

vBe it lrnown that l, JOSEPH Encarna citizen of the lUnited. States, residing in Pittsburgh, in the county-of Allegheny and State of Pennsylvania, havefi-nvented a new and use'fiil improvement inilimmonia and Tar Recovery Processes, of which the following is 'a specification.

This invention relates primarily to the recovery of tar and of ammonia from producer-gas and has for its object the eihcient production of a clean, dust-free and highgrade tar and` of a clean, tar-free and dry ammonium sulfate that has a high content of ammonia and is of the large crystal type and is produced with great economy ot heat or steam and with simplicity and div reetness in the operation of the apparatus; the invention may also be applied to the treatment oi gas that is otherwise derived from the carbonization of coal, and may also have such'other objects and results as are. found to obtain in the processes hereinater set forth and claimed.

ln the accompanying drawings:

Figure 1 is a conventional diagram illustrating an embodiment of the invention .in one arrangement of apparatus for practising its processes.

Fig. 2 is a key to the symbols employed in. the various lines that show the connection between the apparatus indicated in Fig. 1.

Fig. 3 is a conventional .diagram illustrating an embodiment of the invention in another arrangement of apparatus 'for prac-y tising its processes.

Fig. 4 is a key to the symbols employed*- in the various lines that show the connection between the apparatus' indicated in gig. 5 is a conventional diagram illustrating ani embodiment of the invention in lstill another arrangement of apparatus for practising its processes.

Fig. 6 is a key tothe symbols employed in the various lines that show the connection between the apparatus indicated in l ther clean suc Referring now more particularly to Figs. 1 and 2 of the drawings:

There is indicated at 6, a gas-producer" from which the hot evolved producer-gas passes through the gas line 7 to the electrical dust precipitator 8. The producer-gas entering this electrical precipitator. is still at a very high temperature, about 450 C., and therefore it is still greatly superheated with respect to its water and tar, and these, and its other vaporizable content7 are carried as vapori-nto and through said precipitator 8. ln said precipitator 8, the producer-gas Hows in counter-current with water .that enters said precipitator through the water line 9, and7 as a result of the heat interchange between the producer-gas and thea water in said electrical dust precipitator 8, the water is converted into steam which passes to the steam-dome 10 of the electrical dust. precipitator 8 and thence lows out the steam line 11. ln addition to cooling the producer-gas, the electrical dust precipitator 8 acts also to free the passing .gas from dust and other solid impurities in its current. p

rlhe gas, after having been cooled to about 250 C. passes through the gas line 12, still carrying its w'ater and tar as vapor, to the water cooled disintegrator 13 which it leaves at a temperature of about 90 C. At such temperature, the tar, approaching the character ot a finely comminuted mist, has begun tobe precipitated; and' any tar so precipitated in the disintegrator is discharged troduced into the disintegrator 13 through I 'the water line 16 and this water is thorv 95 oughly agitated with the gas in the disintegrator. The effect of the thorough agitation of the gas with the cooling Water in the disinte rater is primarily to flu'- I gas by precipitating any residue of dust or other solid lmpurities.

The partially cooled producer-gas, still carrying the mhjor portion of its tar as vapor, emerges from the disintegrator v13 at a temperature of about 90 C. land passes through the gas line 17 to the electrical vtar precipitator 18 in which the residue of thev tar in the gas will be recipitated; the clean tenso precipitated is ischarged through the tar line 19 into the aforesaid tar tank 15.

The gas passes from said tar-precipitator lution is kept hot by the absorption reaction,

so that there cannot be any diluting oi the ammonia-absorbing acid-solution thatl is owing through said acid-Washer anunonia sulfate disintegrator; and, by` reason olr the super-heat remaining in. the gas, water is ab soi-bed* from the amnioniacharged acid soldim tion, thereby eecting the precipitation of ammonium sulfatel directly in said disintegrator 21. and rendering unnecessary the ent ployment of a separate saturation bath toi: the precipitation of the ammonium sulfate from the ammoniacharged acid-solution. The dew vpoint of the gas may be regulated within. the Water-disintegrator 13 by ,regulating the quantity ci water lied. to the Water-disintegratcr through the, water snp ply line i6, in such manner that. the gas when it reaches the acid-Washer ammonium Sulfate disintegratcr 2l. has enough rernainm ing super-heette ei'ect the precipitation of ammonium sulfate in said disintegrator2L In any event, however, should the gas leave the Water-disintegrator lil at a temperature below that temperature eiifective for the pren cipitation of ammonium sulfate, the ternn Y perature` oi?v the gasinay be raised in the electrical' tarprecipitator 18 by passingiA it in counter-couvent with steam limitingA through said. tar-precioitator The steam may enter the tarprecipitator l@ through the steam line 50 and the Waste steam may discharge thiough the Waste steam line 5l.

From .the acid-Washer ammonium sulfate udisinteg*rater '21, the ammoniadreed gasl Hows through the gas line 22 into the firstm stage natcooler 23, through which it doos in countencuraent With Warm water that enters such cooler at abrutis-50 C., in this cooler, the gas is cooled to about (l, and to a great extent dehydrated, and thence passes through the gas line 2d to the sec'.- ond-sta e dual-cooler 25, through which it passes' 1n counter-current with cold Water at about 25 C. and issues finally dehydrated and cooled 'to a temperature oi" about 25 C, The clean, cool and relatively dry gas is drawn of? through the gas line 26 by the i exhauster 27, andnr passes through said gas line 26 to the gasdiolder '28 from `which the s may be forwarded through -the suppiyn ine 29 to any service it may be employ/@duim The ammonium sulfate and such acd-solution as it may carry with it are drawn ofi from the disintegrator 2l ,through anfiejector line 30 and pass over the dreimtable. 31,- and intatta into' the centrifugal drier 32 from which it isdischarged and carried, in any preferred manner, to the storage pile 'of the lay-product house. from the .centrifugal drier 32 has the dry, clean and large crystal character, with high ammonia content, of the high-grade animo" nium sulfate that may be derived trom the eetmeter-processing ot coke-oven gas.,

'lihe produoergas from the producer, until it reaches the tinal'ooolers' 23, 25, carries unie in such super-heated. condition. is enormously greater than after it has been dehydiatedl and cooled in the final-coolers. ln its dried and cooied condition, a tar less voiune is required to pass through the ex hauster 27, and the exhauster is not required to be of impracticably large dimensions.

The aeid-soiution from the drain-table 31 and alsoany acid-solution drained ofi' from the centrifugai drier v32 is drawn through the acid-line 33 to the acid-pump 34E' and thence is forwarded `through the return acidline 35 to the acid-Washer ammonium sultate disintegrator 2l, which also receives fresh acid from the` acidftank 36. The re turned acidfsolution is stiil suiiiciently heat-- ed to prevent coolinga of the acid-solution that is receiving heat from. the absorption reaction in said disintegrator 21. it. comin: nous circuiation of het acid-solution is'main.- tained through the disintegrator 2l and thence from the drain table 31 and centrifugai. drier 32 bach to said disintegrator 2l.

The aforesaid rst-stageinai-cooler 23 receives its water at a temperature of about 50 and. discharges it at a temperature oii about 89 G.; such discharged hot Water is forced through the hot-Water line 37 by 'lhe aimnoniuin 4suliafs dischaigedl a great amount of Water vapor and its voln the hot-Water pump 38 to the air-saturator tower 39, From the said air-saturator tower 39 the Water issues cooled to a tempera-ture of about ed@ C. and isierced through the Warmwater line 4i() by the Wanna-water pump di, to the said irst-stag'e final-cooler 23 in which the ammonia-freed producergas undergoes the ist stage oi' its final cooling. The second-stage final-cooler 25, how; over, receives a continuous supply of fresh Water, which is forwarded by the fresh Water pump i2 through the fresh-Waterhne 4.3 to said second-stage inalfcoole'r 25:, the drain from said cooler 25 discharges through the drain line di.

' Illhe air that is charged with water-vapor and super-heated and. led to -the gas-producer 6 is dravvixl in from the outside through the fan d5 and thence is forwarded, through the air-line i6 to. the aforesaid airsaturator tower 39, which it enters at a temperature of about 25 C. in this tower 39, the air, passing1 through the Water introduced from the before-mentioned hot-Waimages vapor and issues charged with water-vapor,

` at a temperature of about 80 C., and passes through the air-line 47 to the super-heater 48. ln said super-heater 48, the air is super-heated by passing it in counter-current with Waste flue-gas, for example, stackgas or Waste hot gas from any suitable outside source.

In the super-heater 48, the air is superheated to a very high temperature, and because of this fact, the saturation point of the air is raised enabling the air to carry considerably more Water vapor. This Water vapor is supplied from the steam-line 11 through which the steam generated in the aforesaid electrical dust pre'cipitator 8 iioWs tothe air-line 47 and mixes with the air -before it enters the super-heater 48. The admixed steam has the further eiect of increasing' the temperature of the air before it enters the said super-heater 48. vBy the employment of the electrical dust precipitator as a steam generator, the heat of .the hot producer gas from` the producer is utilized to generate steam Jfor charging the air before it enters the super-heater 48 this expedient renders unnecessary the employment of, or at least reduces the amount of, outside steam for charging the air. The air laden with Water-vapor and heated to a temperature of about 250 C. emerges from the super-heater 48 and passes through the air-line 49 to the grate of the gas-producer 6 Where said air is utilized for the generation of the producergas.

ln the form of the invention illustrated in Figs. 3 and 4, the hot producer-gas flows through the gas-line 7 to the electrical dust precipita-tor 53 in Which said gas flows in counter-current with Water-chargedvair that is conducted from the air-saturator tower 39 through the air-line 47 to said dust-precipitator 53. ln the electrical dust precipitatcr 53, the water-charged air is superheated` and thence the superheated air flows through the air-line 61 to the grate of the producer 6. Before the air enters the dust- -precipitator 53, it is charged with steam from the steam line 52. Otherwise the process illustrated diagrammatically in Figs. 3 and 4 inclusive is the same as that previously described.

Figs. 5 and G illustrate diagrammatically a process substantially identical with that disclosed in Figs. 3 and 4 with the exception that the evolved producer-gas flows through a dust-catcher 54 in counter-'current With the water-charged air instead of through an electrical dust precipitator. ln the dustcatcher. the speed of the gas'is reduced somewhat, whereupon the dust particles which pass over with the gas from the producer drop out from the gas and are precipitated in the bottom of the dust-catcher.

ln the form of the invention illustrated diagra-matically in Fig. 7, the hot producer-'- gas passes through the gas-line 7 to a dustcatcher 54 in which it flows in counter-current With the Water-charged air that 1s going to the producer.Y rlhe air, to Which a portion of steam may be added, enters the dust-catcher 54, through the air-line 47 and passes highly superheated to the grate of the producer 6 through the air-line 61. From the dust -catcher 54, the partiallycooled producer-gas, after having been freed of particles of dust and other foreign matter in its current, passes through the gasline 12 to an electrical dust precipitator 55, in which the gas is freedof any remaining dust or other foreign matter. Thence the dust-freed producer-gas passes through the gas-line 56 to a cooler 57 in which it Hows in counter-'current With cooling Water that enters such cooler through the Water-line 59 and discharges therefrom through the drain-line A60. In the cooler 57, the gas is cooled to about 90 C., and, at such temperature, the tar, approaching the character of a finely comminuted mist, has begun to be precipitated; Aand tar so precipitated in the cooler, is discharged through the tarline 14 into a tar tank 15. From the'cooler 57,A the gas then flows through a gas-line 58 to the electrica-l tar-precipitator 18, the process continuing in substantiallyy the manner describedin connection'yvith Figs. 1 and 2.

The processes of the invention may be practised in various ways, other than the particular embodiment that has been described or purposes of illustration, and still be Within the scope and subject matter of the claims hereinafter made.

1 claim:

1. In a process for the recovery. of tar and ammonia from producer-gas, the combination of steps that consists in: cooling the hot gas from the producer by passing it in counter-current with water to' generate steam and concurrently electrically precipitating the dust from said gas, then further cooling said gas with Water; then electrically precipitating the' tar from the gas and concurrently reheating said gas; then absorbing the ammonia from the dust-freed and tarfreed producer-gas i by passing such gas through anacid-Wash, and concurrently utilizing the heat residuum of the gas to effect deposition of the ammonium sulfate from the ammonia-charged acid-solution; passing the ammonia-freed gas through inal cooling and dehydrating stages; heating and charging the air going to the gas-producer, with Water-vapor, by passing such air in counter-current with the hot Water from the first-stage of the aforesaid final cooling of the gas; conveying the water from said air heating operation back to the first stage of the final gas cooling; furthercharging the throug air from the aforesaid air-heating and Water vapor charging operation with steam generated n the aforesaid dust-precipitation .rently reheating said gas; then absorbing the ammonia from the dust-freed and tarfreed roducer-gas by passing such gas an acid-Wash, and concurrently utilizing the heat residuum of the gas to effect deposition of the ammonium sulfate from the ammonia-"charged acid-solution; passing the ammonia-freed gas through final 4cooling and dehydrating stages; heating and charging the air,V going to the gasproducer, with Water-vapor, by passing such y air in counter-current with the hot Water from the first-stage of the aforesaid final cooling of the gas; conveying the Water from said air heating operation back to the first stage of the final gas cooling; further charging the air from .the aforesaid air-heating and Water vapor charging operation with steam generated in the aforesaid dust-precipitation operation; then again heating the air with waste gas and conveying it to the gas-producer; substantially` as specified.

3. In a process for the recovery of tar and ammonia fromproducer-gas, the combination of steps that consists in: cooling the hot gas from the producer by passing it in counter-current With Water to generate` steam and concurrently electrically precipitating the dust from said gas; then further cooling said gaswith Water; then-electrically precipitating the tar from the gas; then absdrbing the ammonia from the dust-freed and tar-freed producer-gas by passing such gas through an acid-wash, and concurrently utilizing the heat residuum of the gas to effect deposition of the ammonium sulfate fr om the ammonia-charged acid-solution; passing the ammonia-freed gas through final cooling and dehydrating stagesyheating and charging the air going to the gas-producer with Water-vapor, by passing such air in countercurrent with hot Water from the first-stage of'the aforesaid final cooling of the gas; conveying the Water from said air heatin operation back to the first stage of the fina gas cooling; further charging the air from the aforesaid air-heating and water vapor charging operation with steam generated in the aforesaid dust-precipitation operation; then again heating the air and conveying it Eo he gas-producer; substantially asspeci- 4. Ina process for the recoveryof tar and 'ammonia from producer gas, the combination of steps that consists in: cooling the hot gas from the producer by passing it in counter-current with Water to .generate steam and concurrently electrically precipitating the dust from said gas; then further cooling said as with Water; thenelectrically precipitating the tar from the gas; then absorbing the 'ammonia from the dust-freed and tar-freed producer-gas by passing such gas through an acid-Wash, and concurrently utilizing the heatresiduum of the gas to effect deposition of the ammonium sulfate from the ammonia-charged acid-solution; and charging the air going to the gas-producer with the steam generated in the aforesaid dust-precipitation operation; substantially as specified.

5. In a process for the recovery of tar and ammonia' from producer-gas, the combination of steps that consists in: cooling the hot gas from the producer by passing it in counter-current ,with Water to generate steam,-

precipitating the dust from said gas; then further cooling said gas with Watergthen precipitating the tar from the gas; then absorbing the ammonia from the dust-freed andtar-freed producer-gas by passing such gas through an acid-Wash, and concurrently utilizing the heat residuum of the gas to effect deposition of the ammonium sulfate from the ammonia-charged acid-solution;

and charging the air going to the gas-producer with the steam generated in the aforesaid first water-cooling of the gas; substantially as specified. i

6. In a process for the recovery of tar and ammonia from producer-gas, the combination of steps that consists in: cooling the hot as from the )roducer b assino it b l l D in counter-current with water to generate steam, precipitating the dust from said gas; then further cooling said gas with Water; then precipitating the tar from the gas;

then absorbing the ammonia from the dust-l 4freed and tar-freed producer-gas by passing vsuch gas through an acid-wash, land concurrently utilizing the heat residuum of the gas to effect deposition of the ammonium sulfate from the ammonia-charged acid-solution; charging the air going to the gasproducer with the steam generated in the aforesaid first Water-cooling of the gas; then superheating said air before it reaches the gas-producer; substantially` as specified.

7. In a process for the recovery of tar and ammonia from producer-gas, the combination of steps that consists in: 'cooling the hot gas from the producer by passing it in counter-current with Water, precipitating the dust from said gas; then further cooling saidgas with water; then precipi- A tating the tar from the gas; and absorbing specified.

the ammonia from the dust-freed and tarfreed producer-gas by passing such gas through anl acid-Wash, and utilizing 'the heat residuum of the gas to effect deposition of the ammonium sulfate from the ammoniacharged acid-solution; substantially as 8. In a process for the recovery of tar and ammonia from producer-gas, the combination of steps that consists in: cooling the hot gas from the producer by passing it in counter-current with Water and thereby generating steam, precipitating the dust from said gas; then precipitating the tar from the lpartially-cooled gas; conducting the aforesaid steam to the air that isv on its yWay to thegas producer; and then conducting the dust-freed and tar-freed producergas through an ammonia absorbing opera'- tion; the ammonia recovery from the dust and tar-freed gas in the ammonia absorbing Operation being augmented by the addition to the air going to the producer of the steam' generated in the aforesaid cooling opera-y from the partially-cooled gas; conducting the aforesaid steam to preheated and Water charged air that is on its Way to the gas producer; further. heating the steam and Water charged air and conducting it to the producer; and then conducting the dustfreed and tar-freed producer-gas through an ammonia absorbing operation; the ammonia recovery fromthe dust and tar-freed gas in the ammonia absorbing operation being augmented by the addition to the air going to the producer of the steam generated in the aforesaid cooling operation; substantially as specified.`

'10. In a process for the recovery of tar and ammonia from producer as, the combination of steps that consists 1n: subjecting the hot gas from the producer to a primary cooling operation bypassing such gas in counter current with Water and thereby generating steam; removing the tar and ammonia from such gas;and mixing the aforesaid steam with 'the air going to the gas-producer; the ammonia recovery from the gas being augmented by the addition to the air going to the producer of the steam generated in the aforesaid cooling operation; substantially as specified.

11. In a process for the recovery of tar and ammonia from producer-gas, the combination of steps that consists in: concurrently cooling and precipitating the dust from the hot gas from the producer then further cooling and Washing said gas With lWater; then electrically precipitating the tar bination of ,steps that consists in: subjecting the hot gas from the producer to change in speed to precipitate .the dust therefrom; then further cooling and Washing said gas With Water; then electrically recipitating the tar from such partially coo ed, but. still hot gas; and then passing such still hot lgas through an acid wash to absorb the amlmonia; substantially as specilied.

13. In a process for the recovery of tar and ammonia from producer-gas, the combination of steps that consists in: concurrently cooling and precipitating the dust from the hot* gas from the producer; then further cooling and agitating said gas with Water; then electrically precipitating the tar'from such partially cooled, but still hot gas; and then passing Vsaid still hot gas through an acid Wash to absorb the -ammonia; substantially as specified.

14. ln a process for the recovery of tar and ammonia, from tar vand ammonia charged-gas, the combination of stepsthat consists in: concurrently cooling and precipitating the dust from the tar and ammonia charged gas; then further cooling and Washing said gas with Water; then electrically precipitating the tar from such partially cooled, but still hot gas; and then passing such still het gasl through an acid Wash to absorb the ammonia; substantially as specifiedu 15. ln a process for the recoveryof tar and ammonia, from tar and ammonia charged gas, the combination of steps that consists in: concurrently cooling and subjecting the tar and ammonia charged gas to change in speed to ei'ect precipitation of the'dust therefrom; then further cooling and washing said gas with Water; then electrically precipitating the tar from such partially cooled, but still hot gas; and then passing such still het gas through an acid Wash to absorb the ammonia; substantially as specied.

16. In a process for the recovery of tar and ammonia, from tar and' ammonia charged gas, the combination of steps that consists in: concurrently lcooling and precipitating the dust from the tar and am- Inonia charged gas; then electrically precipitating the tar from such partially cooled, but still hot gas; and then passing such still hot gas through an acid Wash to absorb the ammonia; substantially as specilied.

17.- ln a process for the recovery of tar and ammonia from producer-gas the coni-v bination of steps that consists in: eoncurrently cooling and precipitating the dust from the hot gasfrom the producer; then electrically precipitating the tar from such partially cooled, but stillhot gas; and then passing such still hot gas through an acid Wash to absorb .the ammonia; substantially as specified. l

18. In a process for the recovery of tar and ammonia from producer-gas, the combination of steps that consists in: subjecting such gas to a cooling operation; precipitating the dust from the gas; concurrently precipitating the tar from the gas and relie-ating said gas; and then directly effecting the precipitation of ammonium sulfate, by passing such gas through an acid-wash'; the ammonia being absorbed from the gas by the acid-solution and the gas acting as the carrier forthe evaporation from the acidsolu tion through which the gas passes; substantially as specified. v y

19. The process for the recovery of tar and ammonia from producer-gas, which consists in, extracting the tar from hot dustfreed producer-gas, and passing said gas directly from such ltar-extraction to and through a sulfate acid Wash, While said gas still retains sufficient super-heat to effect ydeposition of the ammonium-sulfate from said bath, substantially 4as specified.

20. In a process forthe recovery of tar and ammonia from producer-gas, the' combination of steps that consists in: subjecting.

. cipitating the residue of the dust from said gas; then further cooling said gas by passing it in counter-current with Water then electrically precipitating the tar from the gas;

lthen absorbing the ammonia from the dust' freed` and tar-freed producer-gas by passing such gas through an acid-Wash and concurrently utilizing the heat residuum of the gas to effect deposition of the ammonium sulfate from the ammonia-charged acidsolution; passing the ammonia-freed gas air to the aforesaid primary gas-cooling yopl eration; substantially as specified.

21. The process for the recovery of tar and ammonia from producer-gas, Which consists in: subjecting such gas to a cooling operation, precipitating the dust from the gas, precipitating the tar from the gas, reheating the gas, and then directly effecting the precipitation of ammonium sulfate, by passing such gas' through an acid Wash; substan,

tially as specified. y x

22. The process for the recovery of tar and ammonia from producer-gas, which con sists in: subjecting such gas to a cooling operation, precipitating the dust from the gas, precipitating the tar from the gas, and then directly effecting the precipitation of ain"- monium sulfate, by passing such gas through an acid Wash, the ammonia being absorbed from'the gas by theacid-solution and the gas acting as the carrier for the evaporation from the acid-solution through which the gas passes; substantially as specified.

In testimony whereof I have hereunto set my hand this 15th day of Aueust, 1919.

JosnrriD BECKER. 

